1. Field of the Invention
The present invention relates to a tracking learning/adjusting method of learning a tracking parameter in an optical disk, and an optical disk device using the same method. Here, the optical disk includes, within the single disk, plural record areas whose track-pitches differ from each other.
2. Description of the Related Art
As optical disks, i.e., optical information record media for recording/reproducing information by irradiation with laser light or the like, various types of optical disks have been proposed and have come into practical use. According to, e.g., JP-A-2003-123333, of the various types of optical disks, there has been already known an optical disk which includes, within the single disk, plural record areas whose track-pitches differ from each other depending on the areas. Incidentally, the concrete optical disk proposed in this patent literature is as follows: This optical disk performs the record/reproduction of information by using one and the same generation method of a TE signal even in the areas whose track-pitches differ from each other.
Also, in the optical disk which includes, within the single disk, the plural record areas whose track-pitches differ, as a method of implementing the stable tracking servo, the following method has been disclosed in, e.g., JP-A-2002-25079: Namely, in this method, the track-pitches of the areas are measured each, and, depending on the differences therebetween, the generation method of the tracking error signal (which, hereinafter, will be referred to as “TE signal”) is switched.
This switching is performed because optimum generation methods of the TE signal differ in the respective record areas. For example, assume a case where there are mixed a reproduction-specific compact disk (hereinafter, referred to as “CD-ROM”) area with the track pitch=1.6 μm and one type of digital versatile disks (hereinafter, referred to as “DVDs”), e.g., a reproduction-specific DVD (hereinafter, referred to as “DVD-ROM”) area with the track pitch=0.74 μm. In this case, in the former CD-ROM area, the 3-spot method is the TE signal's optimum generation method. Meanwhile, in the latter DVD-ROM area, the DPD method is the TE signal's optimum generation method.
Moreover, assume a case where there are mixed the above-described DVD-ROM area and a rewritable-type DVD (hereinafter, referred to as “DVD-RAM”) area with the track pitch=0.615 μm. In this case, in the former DVD-ROM area, the DPD method is the TE signal's optimum generation method. Meanwhile, in the latter DVD-RAM area, the Push-Pull method is the TE signal's optimum generation method. In this way, the technology disclosed in JP-A-2002-25079 is, after all, as follows: In the areas whose track-pitches differ from each other, the generation methods which differ from each other and are optimum for the respective areas are used in order to generate the TE signal corresponding thereto. Also, patent literatures JP-A-5-266498 and JP-A-5-266499 have been already known.